Burst Suppression, Geriatric Patient Care Improvement, Postoperative Delirium (POD)
Conditions
Keywords
anaesthesia depth monitoring, geriatric, density spectral array, bispectral index, burst supression, postoperative delirium
Brief summary
This study will be conducted on patients aged 65 and older scheduled for surgery due to lumbar or cervical disc herniation. General anesthesia is routinely used for these types of surgeries in the hospital. In patients receiving general anesthesia, anesthesia depth monitoring is performed. As part of the study, a preoperative anesthesia evaluation will be conducted, which will include age, weight, height, comorbidities, regularly used medications, previous surgical or anesthesia experiences, nutritional habits, mental status, and daily activity levels. On the day of surgery, upon arrival in the operating room, the following will be measured and recorded: * Blood pressure using a non-invasive blood pressure monitor * Heart rate and rhythm via electrocardiogram (ECG) * Blood oxygen level with a pulse oximeter * Anesthesia depth using a forehead-applied sensor All monitoring procedures are non-invasive and painless. Following the placement of these monitoring devices and initial measurements, anesthesia induction and surgery will commence. Throughout surgery, blood pressure, heart rate, and brain activity will be continuously recorded. After the surgical procedure, anesthesia emergence and mental status will be assessed. Preoperative evaluation data and intraoperative recordings will be used solely for research purposes, with patient identity information remaining confidential.
Detailed description
Perioperative cognitive decline and delirium occur more frequently in the geriatric population undergoing surgery. International guidelines recommend monitoring anesthesia depth to reduce the risk of postoperative cognitive dysfunction. Anesthesia depth is commonly measured using non-invasive electroencephalography (EEG)-based methods, such as the Bispectral Index (BIS). Previous studies have predominantly utilized processed EEG monitors that generate numerical values for tracking anesthesia depth. However, in this study, anesthesia depth will be monitored using both the standard numerical BIS index and the Density Spectral Array (DSA) mode, an advanced feature of the BIS device. To date, no studies have simultaneously examined BIS and DSA modes in relation to cognitive function and the recovery process. The use of advanced monitoring techniques may serve as a valuable resource for future research, particularly in optimizing anesthetic management for geriatric patients with reduced cognitive reserve. This study aims to evaluate the effects of different intraoperative anesthesia depth monitoring approaches, including hemodynamic monitoring, numerical BIS values, and DSA functions. The primary objective is to determine the optimal anesthesia monitoring strategy that minimizes intraoperative hypotension, burst suppression, and postoperative delirium.
Interventions
OTHERControl Group: Standard Hemodynamic Monitoring
Anesthesia depth monitoring based on hemodynamic values without additional processed EEG guidance.
DEVICEProcessed Electroencephalogram (BIS Index)
Anaesthesia depth monitoring according to numeric BIS index values.
DEVICEProcessed Electroencephalogram (DSA Mode)
Anaesthesia depth monitoring according to density spectral array functions
Sponsors
Aslıhan Güleç
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Intervention model description
Group 1: Anaesthesia depth monitoring according to hemodynamic values Group 2: Anaesthesia depth monitoring according to numeric BIS values (numbers between 40 to 60 is aimed) Group 3: Anaesthesia depth monitoring according to DSA function (avoiding obvious burst supression and keeping alpha band in high frequency)
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 65 years and older * Elective spinal surgeries * ASA status I-III
Exclusion criteria
* Emergent surgeries * ASA status IV-V * Prediagnosed delirium and or dementia * Inability to give consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Alpha Band Preservation or Loss | Intraoperative (measured continuously from anesthesia induction to emergence) | Alpha band activity (8-12 Hz) in the frontal lobe will be evaluated to determine whether it is preserved or lost during general anesthesia. Alpha band preservation is associated with optimal anesthesia depth and cognitive function preservation, while loss of alpha band activity is linked to increased postoperative cognitive impairment. |
| Intraoperative Hypotension Incidence | Intraoperative (assessed continuously throughout surgery) | Intraoperative hypotension will be measured in 5-minute intervals. Hypotension is a mean arterial pressure (MAP) below 60 mmHg. The episodes of hypotension at any point during surgery will be recorded. |
| Ratio of Burst Suppression | Intraoperative (continuously recorded from anesthesia induction to emergence) | The burst suppression ratio (BSR) will be calculated as the percentage of total anesthesia time spent in burst suppression, as measured by processed electroencephalography (EEG). A higher BSR has been associated with worse postoperative cognitive outcomes. |
| Time of Burst Suppression | Intraoperative (continuously recorded from anesthesia induction to emergence) | Anesthesia time spent in burst suppression (BS), as measured by processed electroencephalography (EEG). A higher BS time has been associated with worse postoperative cognitive outcomes. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Total Intraoperative Remifentanil Consumption | Intraoperative | The total dose of Remifentanil administered intraoperatively will be recorded. Data will be reported as mcg/kg. |
| Total Intraoperative Vasopressor Consumption | Intraoperative | The total dose of vasopressors (noradrenaline, adrenaline, dopamine) administered intraoperatively will be recorded. Data will be reported as mcg/kg. |
| Incidence of Postoperative Delirium Assessed via CAM Scale | Postoperative (assessed at 6, 24, and 48 hours after surgery) | Postoperative delirium will be assessed using the Confusion Assessment Method (CAM) tool. The number of participants meeting the criteria for delirium within the first 48 hours postoperatively will be recorded. |
| Total Intraoperative Propofol Consumption | Intraoperative | The total dose of propofol administered intraoperatively will be recorded. Data will be reported as mg/kg. |
| Total Intraoperative Sevoflurane Consumption | Intraoperative | The total dose of Sevoflurane administered intraoperatively will be recorded. Data will be reported as ml. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Frailty Score Assessed via Clinical Frailty Scale (CFS) | Preoperative (assessed on the day of surgery) | Frailty will be assessed preoperatively using the Clinical Frailty Scale (CFS), which ranges from 1 (very fit) to 9 (terminally ill). Higher scores indicate worse frailty status. The proportion of participants classified as frail (CFS ≥ 5) will be reported. |
Countries
Turkey (Türkiye)
Contacts
Primary ContactAslihan Gulec Kilic, MD
Backup ContactGozde Inan, Associate Professor
Outcome results
None listed